Prosthetic heart valves may be formed from biological materials such as harvested bovine valves or pericardial tissue. These valves are typically fitted within a stent, which may be inserted into the heart at the annulus of the compromised native valve to replace the native valve. To perform an insertion procedure using a minimally invasive transcatheter technique, it may be necessary to compress the stent to a reduced diameter for loading into a delivery device.
Paravalvular (or perivalvular) leak (PVL) is a relatively rare complication related to the replacement of native heart valves. PVL describes a condition of blood flowing between the implanted valve structure and the cardiac tissue rather than through the implanted valve structure as desired. While most PVLs are hemodynamically non-significant, significant leaks may be problematic and require further intervention.